Molecular analysis of Iranian seedless barberries via SSR

Little is known about the genetic diversity of seedless barberry cultivars and its wild type relatives. Microsatellite markers next to the morphological traits were used to distinguish the relatedness of some 47 genotypes; forty-five Iranian genotypes including both seedless cultivars and wild types and two foreign genotypes: Berberis vulgaris and Berberis thunbergii. SSR primers were designed based on seven Mahonia primer pairs. The primers were used to study the polymorphism between collected barberry genotypes. The bands were scored as allelic data to generate a phylogenetic tree. A morphological descriptor bearing sixteen traits was defined and attempted to somewhat establish a correlation to the molecular marker pattern. The primer pairs produced 101 putative alleles. Amongst which GA33 and CA04 had the highest discriminating power and Shannon index. The number of alleles per locus was varied between 6 and 35 alleles, with an average of 14.28. A genetic similarity, more than 82%, was noted amongst seedless cultivars. Cluster analysis of both the markers and the traits next to the principal coordinate analysis of SSRs revealed remarkable relationships between seedless barberry cultivars and Berberis integerrima. Additionally based on the morphological dendrogram, it was established that the B. integerrima genotypes bear more seedless fruits once compared to the other genotypes. In summary, our data were indicative of high genetic variability amongst collected genotypes with B. integerrima being the predominant species in the eastern parts of Iran. Moreover, the Mahonia SSR markers were demonstrated to be highly polymorphic on barberry genus, suggestive to be a proper discriminating tool.